The present invention is generally directed toward syringes used to dispense a flowable material. More particularly, the invention is directed toward such a syringe having a threaded plunger that is used to push the material from the syringe. More specifically, the invention includes such a syringe with a winged grasping structure that allows for improved handling and manipulation of the syringe by a user.
Some competitive syringes (3M for example) have placed winged extensions on the threaded nut, which secures the screw plunger to the syringe barrel. This is undesirable because it directs the use to grasp the nut and not the barrel. By doing so the nut is held stationary and the frictional forces of turning the screw plunger act to unintentionally back the nut off of the barrel. Other syringes (Ultradent, Cosmedent and Vivadent) use a sliding nut mechanism which secures the nut to the barrel and prevents t from turning. This is desirable, but it does not assist the use in getting a better grip on the syringe. Syringes used by Kulzer, Jeneric/Pentron, and 3M incorporate this same sliding nut principle but also incorporate extensions apparently for better gripping but they are either too small to be effective or too thick to fit comfortably in the users hand. The winged extensions on our new syringe are thin like the wings on an airplane and they fit comfortably between the fingers. In addition, they are offset to one side of the barrel providing a comfortable fit in the user""s hand. Still other syringes (Discus and Kerr) simply have a threaded nut on the en of a threaded barrel and don""t o anything to counter act the forces that tend to back off the nut.
It is therefore, an object of the present invention to provide a syringe useful for dispensing dental or other materials.
It is another object of the invention to provide such a syringe that can be easily and efficiently manipulated by the user thereof.
It is still another object of the invention to provide such a syringe useful for the dispensing of materials which is provided with an improved structure for grasping the syringe.
These and other objects of the invention, which will become apparent from the present discussion, are accomplished by the invention as hereinafter described and claimed.
In general, a dispensing syringe comprises a barrel having a through-bore therein extending between and connecting an inlet orifice and an outlet orifice of the barrel. The barrel is also provided with an external keyed and threaded portion proximate to the inlet orifice. A gripping assembly is provided having an internal bore and receivable onto said barrel, by passing said barrel through said bore of said gripping assembly. The bore of said gripping assembly having a complementary shape to at least a portion of the external keyed portion of said barrel, such that when the gripping assembly is received onto said barrel, said external keyed and threaded portion proximate to the inlet orifice of said barrel is physically engaged with the internal complementary portions of the bore of said gripping assembly. The threaded portion of said external keyed and threaded portion proximate to the inlet orifice of said barrel is of sufficient length such that when said gripping assembly is received onto said barrel in the complementary keyed relation, at least a part of the threaded portion of said barrel extends through and physically beyond said gripping assembly. The gripping assembly having at least two opposed wing projection extending therefrom, such that each of said wing projections has at least one surface plane disposed at an angle to a similar surface plane of the other wing projection. The syringe also includes a nut having concentrically disposed first and second diameter threads therein and having a nut through-bore therein, such that said nut is receivable onto said barrel in threaded engagement between said first concentric threads thereof and said external threads of said barrel. The syringe further having an externally threaded plunger receivable within said nut such that the external threads of the plunger threadably interact and cooperate with said second concentric threads of said nut. Said threads of said plunger and said second concentric threads of said nut, being of such cooperating configuration that turning of said plunger in one direction will cause said plunger to advance within said bore of said nut and hence, within said through-bore of said barrel. Material contained within said throughbore will thereby be pushed or caused to move toward said outlet orifice of said barrel to thereby be dispensed therefrom.